ANNOUNCER: Starting right now on ABC's THIS WEEK, a new frontrunner? He's raised the most money this quarter. He's now in a dead heat with Donald Trump.

Will he pull into first?

Dr. Ben Carson joins us only on THIS WEEK.

Plus the Democrats' big week -- Bernie Sanders and Hillary Clinton both claimed victory after the party's first debate.

But will her email scandal haunt her?

And can he capitalize on his performance?

Senator Sanders is with us live.

And final countdown -- as Joe Biden grapples with the decision, we're nearing the first deadline.

Did he tip his hand in a major speech last night?

From ABC News, THIS WEEK WITH GEORGE STEPHANOPOULOS begins now.

(END VIDEOTAPE)

GEORGE STEPHANOPOULOS, ABC HOST: Good morning.

It's been a packed week in politics. The next one could shake things up even more.

Joe Biden closing in on his decision. Some of his top supporters convinced he's ready to jump in the race.

And on the Republican side, Ben Carson neck and neck with Donald Trump, after raising more money from more donors than any Republican candidate this quarter. He's our exclusive hardliner this morning.

And when I asked Donald Trump about Carson on GMA, he previewed a possible line of attack.

(BEGIN VIDEO CLIP)

DONALD TRUMP (R), PRESIDENTIAL CANDIDATE: Ben is a doctor and he's -- that's what he's been doing, and the question is, he is capable of negotiating with China and Russia and Iran and all of the things you have to do?

(END VIDEO CLIP)

Dr. Carson, thank you for joining.

How do you respond to that and why would you be a better president than Donald Trump?

DR. BEN CARSON (R), PRESIDENTIAL CANDIDATE: Well, you know, I don't want to necessarily compare myself with anyone, but I can tell you that, you know, I've had lots of experience doing a whole host of things -- negotiating with all kinds of people in order to get things accomplished. And also bear in mind, there is no one person who does all the negotiation and knows everything. You know, in a multitude of counselors is safety.

So I think that the important thing is to understand what the stakes are. When you go into a negotiation, the recent Iran negotiation, for instance, you have to know how to negotiate. You have to know how to verify, how to make sure that there's appropriate accountability. You have to be able to take down their infrastructure, you have to know what your goals are.

STEPHANOPOULOS: Have you ever done anything like that?

CARSON: If you don't know what your goals are, you're not going to be doing it.

Have I ever done anything like what, negotiate?

STEPHANOPOULOS: Negotiate anything like that?

CARSON: Absolutely.

STEPHANOPOULOS: What's the...

CARSON: I've negotiated many things.

STEPHANOPOULOS: -- best example that would prepare you?

CARSON: Well, for instance, when I became the director of pediatric neurosurgery at Johns Hopkins, pediatric neurosurgery was not even on the map at Hopkins at that point. I had to negotiate a number of things in order to -- to create the various different divisions. And by the time we got to 2008, "U.S. News & World Report" ranked us the number one pediatric neurosurgery unit in the United States.

So, you know, that requires the ability to do things. I had to negotiate with many people in different cities as we were putting The Carson Scholars Fund together. It's now active in all 50 states. As you know, nine out of 10 non-profits fell. Not only that, it has won major national awards that are only given to one philanthropic organization in the country out of tens of thousands. That's not done without having the ability to negotiate.

STEPHANOPOULOS: Donald Trump also suggested that George W. Bush has to share in the blame for 9/11 because it happened on his watch.

What do you make of that?

CARSON: I would probably ask him what he meant by that. I seriously doubt that he's saying that -- that George W. Bush is to blame for it. And -- but beyond that, I would ask him.

STEPHANOPOULOS: You're the only Republican...

CARSON: I certainly -- I certainly don't think so.

STEPHANOPOULOS: You are the only Republican, the only major candidate who opposed President Bush's decision to invade Afghanistan after 9/11.

And I want to show what you said at the debate.

(BEGIN VIDEO CLIP)

CARSON: Declare that within five to 10 years, we will become petroleum independent. The moderate Arab states would have been so concerned about that, they would have turned over Osama bin Laden and anybody else you wanted on a silver platter within two weeks.

(END VIDEO CLIP)

STEPHANOPOULOS: That's what you said he should have done.

But how would that have worked?

How would you have gotten the moderate Arab governments to turn over Osama bin Laden in two weeks?

He'd already been expelled by Saudi Arabia. He was already an enemy of those moderate governments.

CARSON: Well, I think they would have been extremely concerned if we had declared -- and we were serious about it -- that we were going to become petroleum independent, because it would have had a major impact on their finances.

And I think that probably would have trumped any loyalty that they had to -- to people like Osama bin Laden.

STEPHANOPOULOS: But they didn't have any loyalty to Osama bin Laden. The Saudis kicked him out. He was their enemy.

CARSON: Well, you may not think that they had any loyalty to him, but I believe otherwise.

STEPHANOPOULOS: So you believe that had President Bush simply declared energy independence, they would have turned over Osama bin Laden.

How would they have gotten him out of the tribal areas of Afghanistan and Pakistan?

CARSON: I think they would have known where he was. You know, there were indications, for instance, during the Clinton administration that -- that they knew exactly where he was but didn't necessarily pull the trigger.

If -- if we could tell where he was, I'm certain that they knew where he was.

STEPHANOPOULOS: But at that point, we had some idea, but we didn't know for sure.

I simply don't understand how you think this would have worked.

CARSON: Well -- well, here's the point -- here -- here's my point. My point is, we have -- we had other ways that we could have done things. I personally don't believe that invading Iraq was an existential threat to us. I don't think Saddam Hussein was an existential threat to us.

It's a very different situation right now.

Now, we have global jihadists who want to destroy us and our way of life.

STEPHANOPOULOS: But sir, I wasn't...

CARSON: And that is a completely different situation.

STEPHANOPOULOS: I wasn't asking about invading Iraq, I was asking about invading Afghanistan, which had been harboring Osama bin Laden.

CARSON: Well, I was primarily talking about Iraq. You know, I wasn't particularly interested in going into Afghanistan but I do think that we should have taken aggressive action. And I think, you know, creating a base that did not require tens of thousands of our troops, that required a -- a group.

And I think we probably have that number pretty close to right now, about 10,000 or so, and being able to use our drones and being able to use our intelligence and things of that nature, I think that's probably all that was necessary in Afghanistan.

STEPHANOPOULOS: But, sir, when we look back at 9/11, 3,000 people dead on that day. We knew Afghanistan was harboring Osama bin Laden. Ninety percent of the American public supported taking military action, every member of Congress but one.

If that is not a case where you would order retaliation, what is?

CARSON: Well, I just said, I do believe that we should have taken aggressive action. I just don't think necessarily putting tens of thousands of our troops was the correct way to do it.

But, you know, we're talking about things that are in the past. We will never know the answer to that.

And we really need to be concentrating on what are we going to do now to deal with the global jihad threat.

STEPHANOPOULOS: And you've said that you would maintain the military presence in Afghanistan, as President Obama announced this week?

CARSON: Yes, I would. I think we saw what happened in Iraq when we precipitously withdrew. I don't think that we want to make that mistake again. And I'm very happy to see that we have a learning curve there.

STEPHANOPOULOS: And just before I move on, though, I just want to be clear here. So you're standing by the statement that, had President Bush simply declared energy independence back after 9/11, that would have caused the moderate Arab governments to turn over Osama bin Laden?

CARSON: I think they -- I think they would have been extremely concerned about what the ramifications of that would have been. And I believe they would have been considerably more cooperative.

STEPHANOPOULOS: Let's turn to some domestic policy. I was struck by reading your previous book, "America The Beautiful," of things that you wrote there that sound a little bit more like Bernie Sanders than some of your Republican rivals.

In that book, you wrote about taking the positive aspects of socialism and actually implementing them within capitalism.

What did you mean by that?

CARSON: I meant one of the things that happens, for instance, in Europe, for medical school, is that you don't have to pay for it. And, as a result, they don't have the skew that we have here. A lot of people, when they finish medical school, they're hundreds of thousands of dollars in debt.

And instead of, you know, doing what they may have wanted to do, which was maybe be a private -- a primary care doctor, they decide that I'd better become, you know, one of the specialists that makes a lot more money so I can pay this money back.

That's not an issue in Europe and they don't have this -- the kind of primary care deficit that we have.

STEPHANOPOULOS: On health care, you've also said that we have to get rid of for-profit insurance companies.

And in that book, "America The Beautiful," you wrote, "Essentially, all of the insurance companies would have to become non-profit service organizations with standardized regulated profit margins.

"It would be quite reasonable to allow insurance companies a 15 percent annual profit, 5 percent of which would go to the government's national catastrophic health care fund."

How would you do that?

That would require heavy government regulation.

CARSON: Well, I've subsequently switched over to a health savings account. And I find that to be much better.

You know, I was trying to work within the framework of what we have. But I've concluded that what we had simply did not work.

And one of the reasons it didn't work is because insurance companies made profits by denying people care. And that, of course, is a total conflict of interest.

But utilizing the health savings account system that I've talked about more recently, I think, solves that problem.

STEPHANOPOULOS: So you no longer believe that we should get rid of for-profit insurance companies?

CARSON: Well, for-profit insurance companies will become much less relevant with the health savings account system that I've talked about.

STEPHANOPOULOS: How?

CARSON: Because everybody would have a health savings account from the day they are born until the day that they die. We fund it with the same dollars that we use for traditional health care.

We spend almost twice as much per capita on health care as many other nations.

So there's plenty of money there in order to fund those health savings accounts. You give people the ability to shift money within their health savings account within their family, so that each family essentially becomes its own insurance company. There's no middleman. So the money goes a lot further.

It continues to accumulate. It never goes away. And it -- the costs of your catastrophic insurance now drops tremendously because almost everything you're doing is coming out of your health savings account. This works extraordinarily well.

And then for the indigent, you recognize that we already have a way of taking care of them. It's through Medicaid. The annual Medicaid budget is $400 billion to $500 billion a year. We have about 80 million people participating, which is way too many. But we can fix that by fixing the economy.

But dealing with what we have, 80 million into $400 billion goes 5,000 times. Five thousand dollars each man, woman and child, what could you buy with that?

Most concierge practices are $2,000 to $3,000 a year.

And then you still have thousands left over for your catastrophic insurance, which is much cheaper now since everything is coming out of your HSA.

And the interesting thing is people say poor people wouldn't be able to manage a health savings account.

Didn't they say that about food stamps?

Of course they would be able to manage it. They learn very quickly not to go to the emergency room with their diabetic foot ulcer, where it costs five times more; go to the clinic instead, where you get it taken care of plus they say let's get your diabetes under control so you're not back here in three weeks with another problem.

A whole another level of savings that we are not realizing right now. Plus, we're teaching those individuals to be personally responsible and not --

(CROSSTALK)

STEPHANOPOULOS: But those health savings accounts are only $2,000 a person. That's a fraction of what the cost of an average family's health insurance.

CARSON: Well, the $2,000 figure was when I was thinking about the government funding it. But I've subsequently decided the better thing to do is to allow it to be funded through the same channels that regular health care is funded through.

The money is already there, so why change that?

STEPHANOPOULOS: Also in your book, you talked about government regulation. You said that, unfortunately, we decided to deregulate during the 1990s and that paved the way for the economic meltdown in 2008.

Again, that sounds like similar things -- similar to what Bernie Sanders, Martin O'Malley, some of the other Democrats are saying, talking about.

CARSON: Well, certain types of regulations, certain types of regulations. You know, Glass-Steagall, I think, was a very reasonable regulation after what happened on Wall Street in 1929 and in the subsequent decades, because the banks were playing fast and loose with people's hard-earned cash. That needed to be contained.

And then in the '90s, we kind of took the teeth out of that and we started thinking maybe men were angels. But as our founders said, men are not angels, and therefore, we do need government and regulation. So the right kinds are there.

But what we have done instead is we've just ballooned the number of regulations. And every single regulation costs in terms of goods and services.

And who is hit most by that?

Poor people and the middle class. That's what we've got to start thinking about.

STEPHANOPOULOS: So would you reimpose Glass-Steagall?

CARSON: With -- perhaps with some modifications. We certainly need to make sure that we don't have, you know, out-of-control credit default swaps and all kinds of funny money going on. We need to make sure that we protect the people. And that's what the regulations are for.

STEPHANOPOULOS: The United States is about to hit its debt limit on November 3rd.

Do you think it should be raised?

CARSON: Well, you know, we get into this question every single year. I think, you know, it's kind of ridiculous. And we wait until we're right up against the wall and then we say, yes, we've got to raise it or we're going to default. You know, that's craziness.

What we need to do is, at the beginning of the financial cycle, determine where we're going to make the cuts so that we don't wind up in this situation every single year.

STEPHANOPOULOS: But these are bills that have already, you know, we've -- this is money we've already spent. These are bills we have to pay.

CARSON: Well, I recognize that our backs are up against the wall in a couple of weeks and we have to do that in order to prevent a default. I do know that.

However, this should be the last time we have to do it.

STEPHANOPOULOS: So you would raise it this time but not again?

CARSON: I would raise it this time with the stipulation that we are going to go and look at those 645 government agencies and sub-agencies and we're going to find fat and we're going to get rid of that so that we don't have to do this ever again.

CARSON: I personally don't think any of them will be very tough because it's going to be such a clear-cut election. We will be voting about whether we want a nation where the government is in control or a nation where the people are in control. I think it's going to be crystal clear and the people will make a -- a clear decision.

STEPHANOPOULOS: Dr. Carson, thanks for joining us.

CARSON: My pleasure.

STEPHANOPOULOS: And when we come back Bernie Sandesr joins us live. Did he let Hillary off the hook at that debate? Can he convince voters that more socialism is what America needs. That Sunday exclusive is next.

(COMMERCIAL BREAK)

(BEGIN VIDEO CLIP)

UNIDENTIFIED MALE: Senator Sanders, how are you?

LARRY DAVID, COMEDIAN: I'm good. I'm hungry, but I'm good.

And now, if you don't mind, I'm going to dial this right up to a 10.

UNIDENTIFIED MALE: Go right ahead.

DAVID: We're doomed. We need a revolution. Millions of people on the streets. And we've got to do something. And we've got to do it now.

(END VIDEO CLIP)

STEPHANOPOULOS: Larry David doing a dead on Bernie Sanders on Saturday Night Live. Our Sunday exclusive with the real Bernie Sanders is live in just two minutes.

(COMMERCIAL BREAK)

(BEGIN VIDEO CLIP)

SEN. BERNIE SANDERS (I-VT), DEMOCRATIC PRESIDENTIAL CANDIDATE: Let me say something that may not be great politics, but I think the secretary is right, and that is that the American people are sick and tired of hearing about your damn emails.

HILLARY CLINTON (D), PRESIDENTIAL CANDIDATE: Thank you. Thank you.

(APPLAUSE)

(END VIDEO CLIP)

STEPHANOPOULOS: It was the moment of the debate on Tuesday. And now Bernie Sanders joins us live from Iowa this morning. Senator Sanders, thank you for joining us this morning.

You heard that applause in the room after that moment, but a lot of people watching afterwards said you sealed the deal for Hillary with that statement taking away her biggest vulnerability.

Any second thoughts?

SANDERS: Well, I don't think so. I think what the American people want, George, is a discussion in this country of the real issues that are impacting them. And that is they're asking why it is they're working longer hours for low wages, why we have a massive level of income and wealth inequality such that almost all of the new income and wealth is going to the top 1 percent.

They want a discussion to know why it is that we are the only major country on Earth that doesn't provide paid family and medical leave, why they can't send their kids to college, why we have today more people in jail than any other country on Earth, 2.2 million people, and why we're not investing in our young people, in jobs and education rather than more jails and incarceration. Why we are not dealing with the reality of who controls our rigged economy and a corrupt political system, which as a result of Citizens United is allowing billionaires to buy elections, why we are not dealing with climate change, the great global crisis facing our country.

All of those issues are more important than Hillary Clinton's emails, of which there is already a process underway to determine what happens.

STEPHANOPOULOS: Also, big questions about national security. President Obama announcing this week that he would keep almost 10,000 troops in Afghanistan through next year, more than 5,000 after that. You just heard Ben Carson say he supports that decision, so does Hillary Clinton. Do you?

SANDERS: Well, yeah, I won't give you the exact number. Clearly, we do not want to see the Taliban gain more power and I think we need a certain nucleus of American troops present in Afghanistan to try to provide the training and support the afghan Army needs.

STEPHANOPOULOS: You also, at the debate, were asked about when you would authorize the use of force. And you talked about previous votes authorizing use of force, including in Afghanistan.

But you went on to say, "I do not support the U.S. getting involved in unilateral action."

So there are no circumstances where a President Sanders would authorize unilateral action to use force?

SANDERS: Well, I'm not going to get into hypotheticals, but this is what I will say. I would say that the decision -- Bush's decision to get us into a war in Iraq unilaterally was one of the worst foreign policy blunders in the history of the United States. It destabilized the entire region, and led us, in many respects, to where we are today.

I think sensible foreign policy and military policies suggest that it cannot be the United States of America alone which solves all of the world's...

STEPHANOPOULOS: In all circumstances?

SANDERS: -- military...

(AUDIO GAP)

SANDERS: Well, of course, you know, I'm not saying, you know, I don't want to get into hypotheticals. I didn't say in all circumstances. But I do believe, number one, and I think that there's a lesson to be learned from Iraq and Afghanistan, then what a great military power like the United States is about is trying to use diplomacy before war and working with other countries rather than doing it alone.

At the end of the day, coalition -- military coalition is what will succeed, not the United States doing it alone.

STEPHANOPOULOS: Donald Trump took off on you on the stump this week.

Let's take a look.

(BEGIN VIDEO CLIP)

TRUMP: He's going to tax you people at 90 percent. He's going to take everything. And nobody's heard the term communist, but you know what, I call him a socialist/communist, OK, because that's what he is.

(END VIDEO CLIP)

STEPHANOPOULOS: You smiled when you heard that.

What's your response?

SANDERS: Well, if I had to respond to every absurd thing that Donald Trump said, I would spend my whole life doing it. But I do want to -- you raised the issue of taxes. Trump raised that issue.

Let's talk about it. What we have seen, George, in the last 30 years, as most of Americans know, is a massive redistribution of wealth. Unfortunately, it's gone in the wrong direction, it's gone from the middle class and working families to Donald Trump and his friends, the top one tenth of 1 percent.

And, yes, let me be very clear, if we are going to make public colleges and universities to tuition-free, as I believe we have to do in the 21st century, yes, we are going to have a tax on Wall Street speculation.

Yes, we are going to ask Trump and his billionaire friends to pay more in taxes...

STEPHANOPOULOS: What rate?

SANDERS: -- yes, we are going to end these -- we'll come up with that rate. But it will be a damned lot higher than it is right now.

When you see the rich getting much, much richer, and in their effective tax rates, as Warren Buffet often reminds us, is lower than the effective tax rates of truck drivers and nurses, yes, the wealthy have got to pay more and corporations...

STEPHANOPOULOS: You said that...

SANDERS: -- who, in some cases, make billions of dollars, billions of dollars a year in taxes, billions of dollars in profits, don't pay a nickel in taxes.

STEPHANOPOULOS: You said...

SANDERS: That has to change.

STEPHANOPOULOS: You said a damned bit more. Previously, you'd been asked if a 90 percent marginal rate is certainly too high and you said no.

So how high are you willing to go on that top marginal rate?

Are we talking 50 percent?

Sixty percent?

SANDERS: Well, we're working -- George, what we -- this is what we are working on right now. We're going to end the loophole that allows large corporations to stash their money in the Cayman Islands and in some cases, avoid paying all federal income taxes. We are going to raise the estate tax so that Trump and his billionaire friends will -- and their families -- will end up paying more in taxes. We are going to have a tax on Wall Street speculation.

Trillions of dollars have flown -- flowed from the middle class to the top one tenth of 1 percent. And we have got to address the fact that the middle class of this country is disappearing. They need help. We have massive wealth and income inequality. The wealthy are going to have to pay more.

STEPHANOPOULOS: But to pay for all of your programs, you're going to have to do more than tax the top 1 percent.

How far below the top 1 percent are you going to go with tax hikes?

SANDERS: It is not true that we have to go much further. I just indicated to you some of the proposals that we have. The proposals that we have to provide public colleges and universities tuition-free will be paid by a tax on Wall Street speculation. Rebuilding our crumbling infrastructure, a huge need out there, and creating millions of decent jobs will be paid by doing away with the loophole that allows corporations to stash their money in the Cayman Islands tax-free.

We have huge amounts of tax loopholes that exist for the wealthy and large corporations. We're going to address that issue and protect the needs...

STEPHANOPOULOS: So no...

SANDERS: -- of working families and the middle class.

STEPHANOPOULOS: -- tax hikes below the top 1 percent?

No tax hikes below the top 1 percent?

SANDERS: I didn't say that. I think if you're looking about guaranteeing paid family and medical leave, which virtually every other major country has, so that when a mom gives birth, she doesn't have to go back to work in two weeks, or there's an illness in a family, dad or mom can stay home with the kids. That will require a small increase in the payroll tax (INAUDIBLE) Senator Gillibrand's legislation and we can accomplish that with a -- just a small increase in the payroll tax.

STEPHANOPOULOS: But that will...

(CROSSTALK)

SANDERS: -- idea.

STEPHANOPOULOS: That's going to hit everybody.

SANDERS: That would hit every -- yes, it would. But it would mean that we would join the rest of the industrialized world and make sure that when a mom has a baby, she can, in fact, stay home with that baby for three months rather than go back to work at one -- at the end of one week.

We are the only major -- only country -- only major country on Earth that doesn't guarantee paid family and medical leave.

Look, George, the truth of the matter is we do a lot of great things in this country. But we are behind many other countries in protecting the middle class and working families.

And one area that I want to touch on is this week, as you know, the Social Security administration said that there would not be a COLA for our seniors and disabled people. That's only the third time in the last 40 years. I think that's absurd.

Prescription drug costs have gone up. Seniors are paying more. We need to change the formula -- and we've got legislation in to do that, to ascertain what real cost of living is for seniors.

And I am going to fight very hard. You've got millions of seniors trying to get by on $13,000, $14,000 a year making choices between medicine and food. That is criminal. And we've got to change the formula by which COLAs are depended -- are created so that seniors get a fair shake.

STEPHANOPOULOS: Before we go, I've got to show you a little bit of Larry David on "Saturday Night Live."

(BEGIN VIDEO CLIP FROM "SATURDAY NIGHT LIVE," COURTESY NBC)

LARRY DAVID, ACTOR: I'm the only candidate up here who's not a billionaire. I don't have a super PAC. I don't even have a backpack.

(LAUGHTER)

DAVID: I carry my stuff around loose in my arms, like a professor.

(LAUGHTER)

DAVID: You know, between classes.

(END VIDEO CLIP)

STEPHANOPOULOS: He seems to have nailed you.

What do you think?

SANDERS: I think we'll use Larry on our next rally. He does better than I do.

(LAUGHTER)

STEPHANOPOULOS: OK, Bernie Sanders, thanks very much for joining us this morning.

SANDERS: Thank you.

STEPHANOPOULOS: Up next, President Obama changes course on Afghanistan. We'll debate his decision with two veterans of those wars now serving in Congress.

And the roundtable weighs in on Biden's big decision, Trump's staying power and that Benghazi showdown for Hillary.

(COMMERCIAL BREAK)

(BEGIN VIDEO CLIP)

BARACK OBAMA, PRESIDENT OF THE UNITED STATES: This modest but meaningful extension of our presence while sticking to our current narrow missions can make a real difference.

(END VIDEO CLIP)

STEPHANOPOULOS: President Obama on Thursday, reversing course on Afghanistan, announcing 1,000 (ph) U.S. troops will continue to serve in America's longest war even after he leaves office.

Here to weigh in on that, two members of Congress who served in Iraq and Afghanistan, Democratic Tulsi Gabbard, Republican Adam Kinzinger.

Thank you both for joining us.

And Congresswoman Gabbard, let me begin with you. You've long said that it's time to bring our troops home.

So is the president wrong to put his withdrawal plans on hold?

REP. TULSI GABBARD (D), HAWAII: Good morning, George, aloha.

You know, I've supported the president's efforts to continue bringing our troops home and I think it's a good thing that we've gone from having over 100,000 U.S. troops there in Afghanistan to now today having less than 10,000.

Looking at the situation on the ground in Afghanistan, we have a continuing increased presence of both ISIS and Al Qaeda. So I agree with the president's decision to keep some of our troops there, primarily to assist the Afghan security forces, both with intelligence as well as with training as they work to take our common enemy, the Islamic extremists, ISIS and Al Qaeda.

I think it's important, though, as we see some U.S. troops remaining there, that we know exactly what their mission is, that their mission is not to nation-build and to create a mini-America in Afghanistan; it is to work with the Afghan security forces, again, to take out and defeat our common enemy in ISIS, Al Qaeda and others --

(CROSSTALK)

GABBARD: -- extremist groups.

STEPHANOPOULOS: Congressman Kinzinger, some Republicans, including the candidate you support, Jeb Bush, say that may not be enough troops.

Is it?

REP. ADAM KINZINGER (R), ILLINOIS: Well, I don't know. The president, with his military experts, have said 9,800 is going to be what it takes. That's fine.

I mean, here's the thing. A few years -- and I give the president credit for reversing strategy here and saying we're going to maintain this presence.

But two years ago, we could have all predicted this when he said we're going to go down to 5,500 and then just an embassy presence.

Seeing what happened in Iraq and then seeing what the situation in Afghanistan we all knew it was going to happen, which is to the next point, why the president has to say 9,800 troops and then we're going to go to 5,500 by the time I leave office, at the end of the day, announce a strategy and a way to win.

We're going to stay until the Afghan government can stand on its own and not necessarily artificial numbers --

STEPHANOPOULOS: Any reason to think that's any time soon?

KINZINGER: No, it's probably not. We're probably going to be there for a while.

I mean, look, we're still in South Korea. We still have a presence in Kosovo. We have a presence in a lot of places.

So to say we're going to leave 9,800 troops to help the Afghan government be stable, this isn't a -- as Tulsi said -- a 100,000-person combat mission. But this is a very important mission and a very important part of the world. And it's one, frankly, I wish the president would have maintained after 2011 --

(CROSSTALK)

STEPHANOPOULOS: So, Congresswoman Gabbard, the president wrong to keep any timetable at all?

GABBARD: No. I think you've got to look at exactly what's happening on the ground. I would differ with my colleague, Adam Kinzinger, though, that what's happening in Afghanistan is a very different situation than we saw what happened in Iraq.

Our pulling out of U.S. troops of Iraq had nothing to do with the strengthening of ISIS and Al Qaeda. What happened in Iraq that strengthened our enemy there was the sectarian Maliki government that persecuted the Sunni tribes and the Sunni communities. And that began while we were still in Iraq and while we still had a strong presence there.

I think as we look at Afghanistan, the most important thing that we should be doing is saying exactly, what is our mission? You can't have an effective strategy unless you know first exactly what your mission is. And our mission should be to focus on those who attacked us on 9/11 and who continue to wage war against us today.

STEPHANOPOULOS: And that's what the president said on Thursday.

Before we go, a couple of quick political questions:

Congressman Kinzinger, Jeb Bush, out this morning, saying he has grave doubts about Donald Trump's finger on the nuclear trigger; says he's an actor playing the role of a candidate for president.

What do you think of that?

And why do you think that Trump is doing so well and your candidate seems to be stuck in the middle of the pack?

KINZINGER: Well, look, Trump's tapping into this kind of outsider mentality and, of course, Republicans like the idea of somebody fresh coming in.

I think, at the end of the day, slow and steady wins the race. Jeb Bush is the guy that's very competent, was a very conservative governor of Florida. And I think he's correct.

Look, Donald Trump, when he talks about foreign policy, he doesn’t go any further than one layer deep, talking about basically ceding the Middle East to the Russians as ludicrous.

And so I think when people really get to understand beyond what he says on the surface, what he really believes, they'll either see that there's nothing there or it's actually not in line with what Republicans believe and our principles.

STEPHANOPOULOS: And finally, Congresswoman Gabbard, you had kind of a set-to with the chairman of your party, Congresswoman Debbie Wasserman Schultz, saying she's not being honest about why you weren't invited to that debate last week.

You seem to be in a dispute over how many debates there should be; do you think that door is closed now?

Are we set with the debate schedule?

Or you think there can be more?

GABBARD: Oh, first of all, I want to just say I think the facts that have come out with regards to the discourse and conversation that happened last week about my being disinvited from the debate as well as the vice chairs and officers not being included, the facts are out there. I think "The New York Times" and "Bloomberg" have both reported that.

I think that we are hearing a growing number of Democrats and Americans across the country who are calling for more debate, who are calling for getting rid of this exclusivity clause that really punishes our presidential candidates for engaging with different groups and different communities of people across the country, who want to host debate, who want to increase the discourse and conversation, who want to engage.

And I think we've got to continue to push for that so that we can strengthen our party, strengthen our democracy and increase the conversation in our country.

STEPHANOPOULOS: Thank you both for your time this morning.

KINZINGER: You bet.

STEPHANOPOULOS: Up next, is Joe Biden about to shake up this wild race for president?

The roundtable weighs in on all the week's politics when we come back.

(COMMERCIAL BREAK)

(BEGIN VIDEO CLIP)

UNIDENTIFIED MALE: I think with respect to Vice President Biden, they will have a healthy substantive debate if he decides to get in. But as I said last night, I think it's time for him to make that decision.

OBAMA: I'm not going to comment on what Joe's doing or not doing. I think you can direct those questions to my very able vice president.

UNIDENTIFIED FEMALE: Have you made your decision yet?

JOE BIDEN, VICE PRESIDENT OF THE UNITED STATES: I can't hear you.

UNIDENTIFIED FEMALE: Have you made your decision yet?

(END VIDEO CLIP)

STEPHANOPOULOS: Joe Biden having some fun there. Let's talk about it on our roundtable.

And Matt, let me begin with you. You said right after the debate you thought Joe Biden would get in to the race. We're closing in on that time. It could come any day now, this decision.

Do you still believe that?

And how would it change the race?

MATTHEW DOWD, ABC NEWS SPECIAL CORRESPONDENT: Well, yes, I still believe he's going to get in because if he wasn’t getting in, I think you'd be seeing this whole series of other signals in this race.

I thought that after the debate, because you had two main candidates -- Bernie Sanders and Hillary Clinton -- both who did well in the debate, but both who don't have everything the voters want. One has great authenticity -- Bernie Sanders -- and great passion and does very well, but you wonder about his experience. The other one, you -- there's no question about it as they're experience and competent, but there's very little authenticity. Joe Biden comes in and says I have both of those things, it's sort of the Goldilocks candidate -- one is too hot, one is too cold, I'm just right. And that's why he gets in the race.

In the past, is I don't know exactly -- he's got to hope that Bernie Sanders either wins or does very well in Iowa, then wins in New Hampshire, and then the opening is there.

DONNA BRAZILE, DEMOCRATIC STRATEGIST: You know, Mario Cuomo agonized over running for president. And at the end of the day...

STEPHANOPOULOS: Until December.

BRAZILE: That's right. And at the end of the day he said every candidacy needs a rationale.

I agree that Joe Biden brings -- would bring something to the race, and it's not just his personality, I think it's his years of service and of course his support of this president.

But at the end of the day, the invisible primary is over. He has name recognition. People know Joe Biden. But can he compete against Hillary, against Bernie. I saw two candidates last -- this past week who are not just prepared to be president of the United States, but I thought they were great. They were full in on the issues, they represented Main Street. And if Joe Biden gets in, he has to get in, in a race that is already being settled in some states.

STEPHANOPOULOS: Is there room for him?

KATRINA VANDEN HEUVEL, THE NATION: I don't see room. I mean, we've seen Hamlet on the Potomac play out for too long.

But he gets in, I think we saw a debate, as Donna said, you know of ideas, not insults. I think you've got two strong candidates. And President Biden also with -- you know, all respect for the grieving for his son, but he was the architect of the 1994 crime bill, let's not forget that, which has led to the hyper incarceration of people in this country. All of that will come back. And I don't think at this moment, you know, people are fixed on all the issues that will be associated with him, not just his time with President Obama.

STEPHANOPOULOS: Obama...

VANDEN HEUVEL: But -- he's going to head to South Carolina. And in South Carolina, he is going to compete with Hillary for African-American votes. I think it helps Bernie if he comes in.

STEPHANOPOULOS: She's way ahead right now, at least.

BILL KRISTOL, THE WEEKLY STANDARD: Joe Biden is going to get in, I'm quite confident. I think he'll get in tomorrow or Tuesday. He'll go to Delaware, presumably, and announce to his -- the state he represented in the Senate for so many years, I think he will be a strong candidate.

Democrats like President Obama -- even though you couldn't quite remember his name -- and...

(CROSSTALK)

VANDEN HEUVEL: I've moved on. It's...

(CROSSTALK)

KRISTOL: Who has been President Obama, as he will say, his closest partner over these last seven years: Joe Biden. He's been a more sympathetic candidate then Hillary Clinton. He's a more electable candidate then Bernie Sanders. He will signal that he would like to have Elizabeth Warren as his running mate, who I do think is closer to where the average Democratic grassroots type wants the party to go.

A Biden-Warren ticket -- I say this as a Republican -- I think it's the toughest ticket for Republicans. And I think it will be a formidable ticket in the primaries.

VANDEN HEUVEL: I wager a lot -- Senator Warren has a clarion, crystal clear voice on the issues she cares about. And again, Joe Biden was the architect of a bankruptcy bill, which Senator Warren has fought against for decades.

I'm just trying to raise issues here, because I think...

(CROSSTALK)

STEPHANOPOULOS: Let me bring this over to Matt Dowd, though, because some people has said this could actually help Hillary Clinton if he does get in, that she can then run, you know, to the left of Joe Biden, a little bit of change from President Obama, not too much, but to the right of Bernie Sanders. Anything to that?

DOWD: I absolutely disagree with that. I think that's just a rationale so that when Joe Biden gets in, the Hillary Clinton...

STEPHANOPOULOS: You don't really want him in right now.

DOWD: No, you don't really want him in. You don't want to spend all your money in the general election. And I think what Joe Biden really does to Hillary Clinton is surface is a huge vulnerability she has, which points to a general election, which is she has very difficulty with white male working class voters, that's her biggest vulnerability in a general election where she does worse than Republicans do among Latinos. And that's what Joe Biden...

BRAZILE: Matt, we've had this fight in 2008. And I think Hillary proved time and time again during the primaries that she knows how to not only garner the support of white males, but people of color, which is the rise in American electorate.

Look, if Joe Biden gets in the race it's great. It's a competitive race. Hillary knows that. I still believe that the advantages aligns with her. But at the same time Bernie Sanders is a hot commodity right now, not just I think among Democrats, but independents. And I think everyone needs to take a back seat and watch what's going on in the Democratic Party, because Bernie Sanders is out there expanding the electorate, bringing more people into the party, and you know what...

VANDEN HEUVEL: Donna is so right, he's expanding the horizons of what seems possible. So much for the downsized politics that exclude alternatives. In that debate the other night, I'd say progressives won, movements won, and what also won was the understanding that Bernie Sanders brought to the table issues that hadn't been put there.

(CROSSTALK)

VANDEN HEUVEL: ...income inequality, Black Lives Matter.

DOWD: ...that one of the biggest things he's done is we need a reexamination of how capitalism has or has not worked for the vast majority of the country.

STEPHANOPOULOS: And you even saw Bernie Sanders -- I mean, not Bernie Sanders, Ben Carson say there are some positive aspects (inaudible).

I want to talk to you, Bill Kristol, about that as we switch to the Republicans, Bernie, about Carson. Ben Carson continues to rise. Donald Trump fails to fade at all the outsiders still there.

KRISTOL: They're going up. People -- a lot of us, and I include myself -- well, they got the outsiders together. Trump, Carson and Fiorina were on 30, 35 percent about two months ago total, if you add up their three votes. And I thought, well, that's probably enough for the outsiders and we'll get back to normalcy, the elect -- people who have had elective office will garner the majority of the support in the polls and one of them will be nominated.

Now they're above 50 percent. There's no sign of -- Trump has stabilized, sort of plateaued. Carson continues to rise. I think Carson and Sanders have a lot in common -- and I agree with you all, but Sanders has been very -- Carson -- what did Sanders have, 700,000 grass -- donors I think to his campaign.

VANDEN HEUVEL: ...well, two-thirds -- he got what he has is this great network of small donors.

KRISTOL: No, but 700,000 small donors and Carson has 600,000 small donors...

DOWD: Big engine.

VANDEN HEUVEL: Big engine.

KRISTOL: Big engine. They can go back to them. They can get more money. Predicting that somehow Carson is going to fade or even Trump is going to fade, whether Fiorina isn't a plausible nomination...

STEPHANOPOULOS: Although she has really seemed to stall.

DOWD: She has -- I think what Fiorina has -- the biggest problem she has, she goes up in the debate because she does very well in 60-90 second answers, much better on those answers in the debate than every other establishment candidate that we've seen out there that's supposedly been in office doing well. But she has no stickiness to her vote. It always drops back, right back down. So she runs no campaign between the debates. I think that's problematic for her.

And the other thing about Donald Trump is, is that everybody keeps -- every time everybody says he's going to fail. He did poorly. It's going to drop. There's an element of votes in this country, maybe it's 25, 26, 24 percent that has stuck on Donald Trump. In a multi-candidate field with more than five or six candidates, that's enough to win.

STEPHANOPOULOS: Which is why you see Jeb Bush coming out hard at him right now. And his campaign has put out an ad taking on Donald Trump. We've heard Jeb Bush this morning. Let's take a look at the ad.

(BEGIN VIDEO CLIP)

TRUMP: You say, you know, dealing with killers. People that go ah ah ah.

UNIDENTIFIED FEMALE: Donald Trump doesn't like to be questioned on the issues.

UNIDENTIFIED MALE: Trump is weak on policy.

UNIDENTIFIED MALE: When you are running for the presidency of the United States of America, the most important title is commander-in-chief. He should have a working knowledge.

(END VIDEO CLIP)

VANDEN HEUVEL: But Jeb Bush doesn't have much -- there's not enthusiasm -- there's little enthusiasm for him in the streets or the suites. I mean, what he does have -- and I don't know how it's going to play in this outsider kind of election -- you've got 158 families in this country, essentially funding half of this campaign so far. That Super PACs that start money.

Jeb Bush has that kind of money, but we may be witnessing an election, which is going to rewrite the rules. And...

DOWD: ...ad -- if you were a Republican voter that was for either Donald Trump or Ben Carson or Carly Fiorina, that ad would be more -- you would be more for them in the aftermath of that ad.

The other thing this election has demonstrated is big money doesn't matter. If you have a message -- no, it doesn't. Because in the course of this every bit of money that has been spent hasn't moved voters. What's moved voters is some connection with the voters and that's what Ben Carson has, that's what Donald Trump has.

(CROSSTALK)

KRISTOL: Let's remember, this was supposed to be the joint Clinton-Bush coronation. And isn't it amazing how little it is. On the Republican side, not at all. Bush is running...

(CROSSTALK)

DOWD: And neither is going to be the nominee.

BRAZILE: This is supposed to be the year of...

UNIDENTIFIED MALE: We're going to have a Sanders-Biden showdown.

(CROSSTALK)

UNIDENTIFIED MALE: We're going to have a Sanders-Biden showdown on the Democratic side.

VANDEN HEUVEL: You know, but there is...

UNIDENTIFIED MALE: And Jeb may not make it in...

VANDEN HEUVEL: But there is a real...

(CROSSTALK)

VANDEN HEUVEL: There is a reason we're seeing the rules being rewritten.

UNIDENTIFIED MALE: Yes.

VANDEN HEUVEL: This country is angry. It's come out of the greatest...

(CROSSTALK)

VANDEN HEUVEL: -- financial crisis since the Great Depression.

(CROSSTALK)

VANDEN HEUVEL: And politicians haven't been speaking to it. So you have a Bernie Sanders and I mean the problem with Trump is he tries to...

(CROSSTALK)

BRAZILE: George, I just want to say, this is a big week for Hillary Clinton. I'm neutral, so I've got to say this. She goes before the Benghazi Committee. I think the Benghazi Committee is going to be the one under investigation after this week. I think Hillary is going to be able to answer those questions and prove that they have spent $5 million of the taxpayers' money not getting to the bottom of what happened in Benghazi...

(CROSSTALK)

UNIDENTIFIED MALE: Her extensive emails with Sid Blumenthal, someone who's so crazy that President Obama...

BRAZILE: Did you see the CIA...

UNIDENTIFIED MALE: Prohibited...

BRAZILE: Did you see the CIA...

UNIDENTIFIED MALE: -- prohibited...

BRAZILE: -- letter yesterday?

UNIDENTIFIED MALE: Prohibited...

(CROSSTALK)

BRAZILE: Did you see the CIA...

(CROSSTALK)

UNIDENTIFIED MALE: President Obama...

BRAZILE: No, no, no. You're getting heated up...

UNIDENTIFIED MALE: -- stopped...

BRAZILE: -- because of Hillary, because you cannot see her in this vision.

But Hillary Clinton...

UNIDENTIFIED MALE: I can see Benghazi and I can see her failure in Benghazi.

BRAZILE: Of course, she -- she has admitted her problems and her mistakes. But where has the Republicans investigating this brought in the Intelligence Committee, brought in the defense community?

They have not. They've been investigating...

VANDEN HEUVEL: Could I...

BRAZILE: -- Hillary Clinton's emails.

VANDEN HEUVEL: -- could I have a contrarian view -- contrarian view on this?

(CROSSTALK)

VANDEN HEUVEL: This Benghazi Committee has become more show trial than of value. It's hyper-partisanized.

But there is a le...

STEPHANOPOULOS: But that's not a contrarian view.

VANDEN HEUVEL: But -- no, but the legit -- no, but here's the le -- there is a legitimate role for a committee...

UNIDENTIFIED MALE: Right.

VANDEN HEUVEL: -- that investigates why it is that the policy of the United States is regime change, which was Hillary Clinton and Obama's policy in Libya, which led to some of the crisis we're witnessing with ISIS and Syria.

And we should have a discussion in this country about you -- why U.S. foreign policy is not a different one and why we need a different one.

UNIDENTIFIED MALE: And the Republicans were smart. If the Republicans were smart, which is a big if, in the course of this and what's going on in Congress -- I don't know if that's possible. But they would not -- Benghazi is not her vulnerability. Benghazi is not Hillary Clinton's vulnerability.

VANDEN HEUVEL: -- as much as he was saying enough with this media that doesn't ask serious questions...

BRAZILE: Right.

VANDEN HEUVEL: -- about the middle class, about the way the system is rigged. That's what he was doing in that motion.

But it was a great moment in the debate.

KRISTOL: And subtly reminding people about the emails at the same time that he...

(CROSSTALK)

KRISTOL: -- at the same time that he pretending to defend her.

(CROSSTALK)

DOWD: I don't think he pretended.

STEPHANOPOULOS: That is going to have to be...

VANDEN HEUVEL: No, I think he (INAUDIBLE).

STEPHANOPOULOS: -- the last word right now.

Thank you all very much.

And our Sunday Spotlight is next after this from our ABC stations.

(COMMERCIAL BREAK)

STEPHANOPOULOS: As America grapples with a surge of gun violence in our big cities and rising tensions between police and the communities they serve, our Sunday Spotlight shines on a new program in our nation's capital that's trying to bring those tensions down and save young lives.

Here's Pierre Thomas.

(BEGIN VIDEOTAPE)

PIERRE THOMAS, ABC NEWS CORRESPONDENT (voice-over): It's a beautiful morning along the Potomac River and that canoe is carrying a group of kids from inner city DC, picked from neighborhoods with the highest homicide rates.

They've been brought here by DC cops they hardly know.

UNIDENTIFIED MALE: You guys hear that?

UNIDENTIFIED MALE: No gunshots. No sirens.

THOMAS: It's orientation day for one group in the city's Youth Creating Change program, looking to transform the way more than two dozen teens view police...

UNIDENTIFIED CHILD: Keep climbing.

THOMAS: -- and themselves.

Seventeen-year-old Tamajey Edwards (ph) is basking in the serenity.

TAMAJEY EDWARDS: I mean quiet. I like quiet.

(singing)

THOMAS: But only days later, Tamajey is carrying the casket of his cousin, Devan Boggs (ph), a brother-like figure gunned down just across the DC line.

UNIDENTIFIED FEMALE: Because someone got shot. Yes. Yes.

THOMAS: At the funeral, a community leader chastises the young people.

UNIDENTIFIED MALE: Do black lives really matter?

THOMAS: Telling them they're part of the problem.

UNIDENTIFIED MALE: He would not be where he is if some of you would have said something to somebody who knew what was going on.

THOMAS: The murder remains unsolved, as the nation's capital battles a near 50 percent increase in homicides.

UNIDENTIFIED MALE: So y'all need to start looking at spikes that can be redone.

THOMAS: Even a ride with police for a community service project has its dangers. Tamajey and Danye (ph) keep ducking into their seats.

UNIDENTIFIED MALE: You can't be seen up there.

THOMAS: They're not playing games.

UNIDENTIFIED MALE: Those neighborhoods are actually, you might say, at war, but they have a beef.

THOMAS: A threat of violence these kids know all too well.

(on camera): How many of you guys have heard gunshots in your neighborhood?

UNIDENTIFIED MALE: All of us.

THOMAS: How many know someone who's been shot over (INAUDIBLE)?

UNIDENTIFIED MALE: All of us.

THOMAS (voice-over): To slow the violence, many believe the young people must start to trust police.

UNIDENTIFIED MALE: Some police think they can do what they want. And that ain't true all the time.

UNIDENTIFIED MALE: People will be like, well, I don't want to work with the police. But then when they get with us and they hit hard and they see we having fun and want to have fun just like them, we're just like them.

THOMAS: Five weeks in, the young people end up somewhere many never imagined.

UNIDENTIFIED MALE: Oh, come on, man!

UNIDENTIFIED MALE: Drop the blade!

THOMAS: The police training academy.

UNIDENTIFIED FEMALE: We let them see what -- what it's like to be on a traffic stop, to be the police officer and stop a car.

UNIDENTIFIED MALE: How fearful were you?

UNIDENTIFIED MALE: I was kind of fearful when he got out of the car because (INAUDIBLE).

UNIDENTIFIED MALE: So now, when you guys are out there hear the news saying a police did something, just shot this kid, you can relate now and say, oh, you know what, it might be more to that story.

THOMAS: Over the weeks and months we followed the teens, we see a transformation. On graduation day at FedEx Field, there's now pride and that elusive trust with police.

UNIDENTIFIED MALE: At first, I didn't like them. Now, I look at them different. (INAUDIBLE) like they took me in as one of them.

THOMAS: The young people are now embracing police, trying to navigate the violence around them.

UNIDENTIFIED MALE: We've got to keep moving forward and doing the best you can.

UNIDENTIFIED MALE: Just look.

THOMAS: For THIS WEEK, Pierre Thomas, ABC News, Washington.

(END VIDEO TAPE)

STEPHANOPOULOS: So great to see that progress.

That is all for us today. Thanks for sharing part of your Sunday with us. Check out "WORLD NEWS TONIGHT" and I'll see you tomorrow on GMA.

(END OF SHOW)

Full transcript of the interview with Ben Carson:

GEORGE STEPHANOPOULOS, HOST: Dr. Carson, thank you for joining us today.

So you and Donald Trump head-to-head at the top of the GOP polls right now.

When I spoke with him on "GMA" this week, he questioned whether you have the capacity and experience to negotiate with China, Russia and Iran.

How do you respond to that and why would you be a better president than Donald Trump?

BEN CARSON (R), PRESIDENTIAL CANDIDATE: Well, you know, I don't want to necessarily compare myself with anyone, but I can tell you that, you know, I've had lots of experience doing a whole host of things -- negotiating with all kinds of people in order to get things accomplished. And also bear in mind, there is no one person who does all the negotiation and knows everything, you know. In a multitude of counselors is safety.

So I think that the important thing is to understand what the stakes are. When you go into a negotiation, the recent Iran negotiation, for instance, you have to know how to negotiate. You have to know how to verify, how to make sure that there's appropriate accountability. You have to be able to take down their infrastructure, you have to know what your goals are.

STEPHANOPOULOS: Have you ever done anything like that?

CARSON: If you don't know what your goals are, you're not going to be doing it.

Have I ever done anything like what, negotiate?

STEPHANOPOULOS: Negotiate anything like that?

CARSON: Absolutely.

STEPHANOPOULOS: What's the j

CARSON: I've negotiated many things.

STEPHANOPOULOS: -- best example that would prepare you?

CARSON: Well, for instance, when I became the director of pediatric neurosurgery at Johns Hopkins, pediatric neurosurgery was not even on the map at Hopkins at that point. I had to negotiate a number of things in order to -- to create the various different divisions. And by the time we got to 2008, "U.S. News & World Report" ranked us the number one pediatric neurosurgery unit in the United States.

So, you know, that requires the ability to do things. I had to negotiate with many people in different cities as we were putting The Carson Scholars Fund together. It's now active in all 50 states. As you know, nine out of 10 non-profits fell. Not only that, has won major national awards that are only given to one philanthropic organization in the country out of tens of thousands.

That's not done without having the ability to negotiate.

STEPHANOPOULOS: Donald Trump also suggested that George W. Bush has a share in the blame for 9/11 because it happened on his watch.

What do you make of that?

CARSON: I would probably ask him what he meant by that?

I seriously doubt that he's saying that -- that George W. Bush is to blame for it. And -- but beyond that, I would ask him.

STEPHANOPOULOS: You're the only Republican...

CARSON: I certainly -- I certainly don't think so.

STEPHANOPOULOS: You are the only Republican, the only major candidate who opposed President Bush's decision to invade Afghanistan after 9/11. I want to show what you said at the debate.

(BEGIN VIDEO CLIP)

CARSON: Declare that within five to 10 years, we will become petroleum independent. The moderate Arab states would have been so concerned about that, they would have turned over Osama bin Laden and anybody else you wanted on a silver platter within two weeks.

(END VIDEO CLIP)

STEPHANOPOULOS: That's what you said he should have done.

But how would that have worked?

How would you have gotten the moderate Arab governments to turn over Osama bin Laden in two weeks?

He'd already been expelled by Saudi Arabia. He was already an enemy of those moderate governments.

CARSON: Well, I think they would have been extremely concerned if we had declared -- and we were serious about it -- that we were going to become petroleum independent, because it would have had a major impact on their finances.

And I think that probably would have trumped any loyalty that they had to -- to people like Osama bin Laden.

STEPHANOPOULOS: But they didn't have any loyalty to Osama bin Laden. The Saudis kicked him out. He was their enemy.

CARSON: Uh, well, you may not think that they had any loyalty to him, but I believe otherwise.

STEPHANOPOULOS: So you believe that had President Bush simply declared energy independent, they would have turned over Osama bin Laden.

How would they have gotten him out of the tribal areas of Afghanistan and Pakistan?

CARSON: I think they would have known where he was. You know, there were indications, for instance, during the Clinton administration that -- that they knew exactly where he was but didn't necessarily pull the trigger.

If -- if we could tell where he was, I'm certain that they knew where he was.

STEPHANOPOULOS: But at that point, we had some idea but we didn't know for sure.

I simply don't understand how you think this would have worked.

CARSON: Well -- well, here's the point -- here -- here's my point. My point is, we have -- we had other ways that we could have done things. I personally don't believe that invading Iraq was an existential threat to us. I don't think Saddam Hussein was an existential threat to us.

It's a very different situation right now.

Now, we have global jihadists who want to destroy us and our way of life.

STEPHANOPOULOS: But sir, I wasn't...

CARSON: And that is a completely different situation.

STEPHANOPOULOS: I wasn't asking about invading Iraq, I was asking about invading Afghanistan, which had been harboring Osama bin Laden.

CARSON: Well, I was primarily talk -- talking about Iraq. You know, I wasn't particularly interested in going into Afghanistan but I do think that we should have taken aggressive action. And I think, you know, creating a base that did not require tens of thousands of our troops, that required a -- a group.

And I think we probably have that number pretty close to right now, about 10,000 or so and being able to use our drones and being able to use our intelligence and things of that nature, I think that's probably all that was necessary in Afghanistan.

STEPHANOPOULOS: Sir, when we look back at 9/11, 3,000 people dead on that day. We knew Afghanistan was harboring Osama bin Laden. Ninety percent of the American public supported taking military action. Every member of Congress but one. If that is not a case where you would order retaliation, what is?

CARSON: Well, I just said, I do believe that we should have taken aggressive action. I just don't think necessarily putting tens of thousands of our troops was the correct way to do it.

But, you know, we're talking about things that are in the past. We will never know the answer to that.

We really need to be concentrating on what are we going to do now to deal with the global jihad threat.

STEPHANOPOULOS: And you've said that you would maintain the military presence in Afghanistan as President Obama announced this week?

CARSON: Yes, I would. I -- I think we saw what happened in Iraq when we precipitously withdrew. I don't think that we want to make that mistake again. And I'm very happy to see that we have a learning curve there.

STEPHANOPOULOS: And just before I move on, though, I just want to be clear here. So you're standing by the statement that had President Bush simply declared energy independence back after 9/11, that would have caused the moderate Arab governments to turn over Osama bin Laden?

CARSON: I think they -- I think they would have been extremely concerned about what the ramifications of that would have been. And I believe they would have been considerably more cooperative.

STEPHANOPOULOS: Let's turn now to some domestic policy. I was struck by reading your previous book, "America The Beautiful," of things that you wrote there that sound a little bit more like Bernie Sanders than some of your Republican rivals.

In that book, you wrote about taking the positive aspects of socialism and actually implementing them within capitalism.

What did you mean by that?

CARSON: Well, I meant one of the things that happens, for instance, in Europe, for medical school, is that you don't have to pay for it. And as a result, they don't have the skew that we have here. A lot of people, when they finish medical school, they're hundreds of thousands of dollars in debt. And instead of, you know, doing what they may have wanted to do, which was maybe be a private -- a primary care doctor, they decide that I'd better become a, you know, one of the specialists that makes a lot more money so I can pay this money back.

That's not an issue in Europe and they don't have the kind of primary care deficit that we have.

STEPHANOPOULOS: On health care, you've also said that we have to get rid of for-profit insurance companies. And in that book, "America The Beautiful," you wrote, "Essentially, all of the insurance companies would have to become non-profit service organizations with standardized regulated profit margins. It would be quite reasonable to allow insurance companies a 15 percent annual profit, 5 percent of which would go to the government's national catastrophic health care fund.

How would you do that?

That would require heavy government regulations?

CARSON: Well, I've subsequently switched over to a health savings accounts. And I find that to be much better. You know, I was trying to work within the framework of what we have. But I've concluded that what we have simply did not work.

And one of the reasons it didn't work is because insurance companies made profits by denying people care. And that, of course, is a total conflict of interest.

But utilizing the health savings accounts system that I've talked about more recently I think solves that problem.

STEPHANOPOULOS: So you no longer believe that we should get rid of for-profit insurance companies?

CARSON: Well, for-profit insurance companies will become much less relevant with the health savings account system that I've talked about.

STEPHANOPOULOS: How?

CARSON: Because everybody would have a health savings account from the day they are born until the day that they die. We fund it with the same dollars that we use for traditional health care. We spend almost twice as much per capita on health care as many other nations. So there's -- there's plenty of money there in order to fund those health savings accounts. You give people the ability to shift money within their health savings account within their family, so that each family essentially becomes its own insurance company. There's no middleman. So the money goes a lot further.

It continues to accumulate. It never goes away. And it -- the costs of your catastrophic insurance now drops tremendously because almost everything you're doing is coming out of your health savings account. This works extraordinarily well.

And then for the indigent, you recognize that we already have a way of taking care of them. It's through Medicaid. The annual Medicaid budget is $400 billion to $500 billion a year. We have about 80 million people participating, which is why too many. But we could fix that by fixing the economy.

But dealing with what we have, 80 million into $400 billion goes 5,000 times. Five thousand dollars each man, woman and child, what could you buy with that?

Most concierge practices are $2,000 to $3,000 a year.

And then you still have thousands left over for your catastrophic insurance, which is much cheaper now since even though is coming out of your HSA.

And the interesting thing is people say poor people wouldn't be able to manage a health savings account.

Didn't they say that about food stamps?

Of course they would be able to manage it. They learn very quickly not to go to the emergency room with their diabetic foot ulcer, where it costs five times more, go to the clinic instead, where you get it taken care of plus they say let's get your diabetes under control so you're not back here in three weeks with another problem.

A whole another level of savings that we are not realizing right now. Plus, we're teaching those individuals to be personally responsible and not (INAUDIBLE)...

STEPHANOPOULOS: But those health savings accounts is only $2,000 a person. That's a fraction of what the cost of an average family's health insurance.

CARSON: Well, the -- the $2,000 figure was when I was thinking about the government funding it. But I've subsequently decided the better thing to do is to allow it to be funded through the same channels that regular health care is funded through. The money is already there, so why change that?

STEPHANOPOULOS: Also in your book, you talked about government regulation. You said that unfortunately, we decided to deregulate during the 1990s and that paved the way for the economic meltdown in 2008.

Again, that sounds like similar things -- similar to what Bernie Sanders, Martin O'Malley, some of the other Democrats are saying, talking about...

CARSON: Well, certain types of regulations. Certain types of regulations. You know, Glass-Steagall, I think, was a -- a very reasonable regulation after what happened on Wall Street in 1929 and in the subsequent decades, because the banks were playing fast and loose with people's hard-earned cash.

That needed to be contained.

And then in the '90s, we kind of took the teeth out of that and we started thinking maybe men were angels. But as our founders said, men are not angels, and therefore, we do need government and regulation. So the right kinds are there.

But what we have done instead is we've just ballooned the number of regulations. And every single regulation costs in terms of goods and services.

And who is hit most by that?

Poor people and the middle class. That's what we've got to start thinking about.

STEPHANOPOULOS: So would you reimpose Glass-Steagall?

CARSON: Uh, with -- perhaps with some modifications. We -- we certainly need to make sure that we don't have, you know, out of control credit default swaps and all kinds of funny money going on. We need to make sure that we protect the people. And that's what the regulations are for.

STEPHANOPOULOS: One final question from that book on immigration. You wrote, "Is it moral for us to take advantage of cheap labor from illegal immigrants while denying them citizenship? F

I'm sure you can tell from the way I phrased the question that I believe we have taken the moral low road on that issue."

If that's the moral low road, then why do you -- then why not support a path to citizenship for undocumented immigrants?

CARSON: Well, what I support is giving them, if they have a pristine record, an opportunity to register as guest workers so they're not, you know, living subterranean. You know, they're above ground. They have to pay, you know, a back tax penalty and they have to pay their taxes going forward. And they have to maintain a pristine record.

And they don't get to vote. They aren't citizens, but they're not living beneath ground and they have something that they prefer.

But my long-term plan would be for us to allow, you know, American businesses to do the same kind of thing they're doing in Cameroon right now, going over there, developing the acreage, you know, creating jobs and creating opportunities and teaching those people the ag business, and while, at the same time, making profit.

If we do that in Central America and South America and help them to be able to improve their own standard of living there, they won't need to come here.

STEPHANOPOULOS: But why not support a path to citizenship?

CARSON: Well, I had talked about a path to citizenship before, but it would include, you know, leaving the country and -- and doing what any other citizen wants to do in order to get here. I wouldn't preclude somebody from being able to do that. But I certainly wouldn't reward somebody for breaking the law.

STEPHANOPOULOS: The United States is about to hit its debt limit on November 3rd.

Do you think it should be raised?

CARSON: Well, you know, we get into this question every single year. I think, you know, it's kind of ridiculous. And we wait until we're right up against the wall and then we say yes, we've got to raise it or we're going to default. You know, that's craziness.

What we need to do is at the beginning of the financial cycle determine where we're going to make the cuts so that we don't wind up in this situation every single year.

STEPHANOPOULOS: But these are bills that have already, you know, we've -- this is money we've already spent. These are bills we have to pay.

CARSON: Well, I recognize that our backs are up against the wall in a couple of weeks and we have to do that in order to prevent a default. I do know that.

However, this should be the last time we have to do it.

STEPHANOPOULOS: So you would raise it this time but not again?

CARSON: I would raise it this time with the stipulation that ew are going to go and look at those 645 government agencies and sub-agencies and we're going to find fat and we're going to get rid of that so that we don't have to do this ever again.

CARSON: I personally don't think any of them will be very tough because it's going to be such a clear-cut election. We will be voting about whether we want a nation where the government is in control or a nation where the people are in control. I think it's going to be crystal clear and the people will make a -- a clear decision.